Systems currently on the market provide parking status indicators on displays to convey how many spaces in a parking garage are currently available. Such systems use occupancy sensors to determine whether a space is vacant or empty. Moreover, illumination lighting sources currently available on the market can be controlled by occupancy sensors to dim the illumination lighting sources for energy efficiency purposes. But the current solutions do not integrate the display and illumination lighting source together, which is sub-optimal.
While displaying the number of spaces available is useful to the user to understand the current vacancy status of the parking garage, the displays and illumination lighting provide no guidance to the user for what is the best action or most likely next action to take to find an empty parking space. Nor do the display or illumination lighting sources guide the user to help the user find their vehicle when the user desires to leave the parking garage. Thus, an inexperienced user may experience frustration or difficulty understanding what to do if they wish to find a parking space for their vehicle or in attempting to locate their parking space when they cannot remember where they parked. Improvements in display lighting and illumination lighting and controls of a lighting system are needed to overcome these or other limitations in the art.
Moreover, lighting equipment for illumination and displays for image output have fundamentally different requirements, for example, for consumer applications.
Electrically powered artificial illumination lighting has become ubiquitous in modern society. Electrical lighting equipment is commonly deployed, for example, in homes, buildings of commercial and other enterprise establishments, as well as in various outdoor settings.
In conventional luminaires, the luminance output can be turned ON/OFF and often can be adjusted up or dimmed down. In some devices, e.g., using multiple colors of light emitting diode (LED) type sources, the user may be able to adjust a combined color output of the resulting illumination. The changes in intensity or color characteristic of the illumination may be responsive to manual user inputs or responsive to various sensed conditions in or about the illuminated space.
There also have been proposals to use displays or display-like devices mounted in or on the ceiling to provide variable lighting. The Fraunhofer Institute, for example, has demonstrated lighting equipment using luminous tiles, each having a matrix of red (R) LEDs, green (G), blue (B) LEDs and white (W) LEDs as well as a diffuser film to process light from the various LEDs. The LEDs of the system were driven to simulate or mimic the effects of clouds moving across the sky. Although use of displays allows for variations in appearance that some may find pleasing, the displays or display-like devices typically have been optimized for image output and do not provide particularly good illumination for general lighting applications. A display typically has a Lambertian output distribution over substantially the entire surface area of the display screen, which does not provide the white light intensity and coverage area at a floor or ceiling height offered by a similarly sized ceiling-mounted light fixture.
Liquid crystal displays (LCD) also are rather inefficient. For example, backlights in LCD televisions have to produce almost ten times the amount of light that is actually delivered at the viewing surface. Therefore, any LCD displays that might be used as lighting products need to be more efficient than typical LCD displays for the lighting device implementation to be commercially viable.
Projection displays are typically cost effective alternatives to direct-view displays such as LCDs, when large area and high brightness are desired. But the color quality and light distribution from prior projection displays are not sufficient for general lighting applications.
Examples of other uses of lighting in combination with display technologies include various configurations of signage that include light sources as backlighting that are positioned behind a design feature such a diffuser or screen with an image or wording. Examples of such backlit signage includes advertising signs, door exit signs and other examples of signage that would benefit from backlighting. Some of the signs may be controllable to change wording or an image presented on the display device of the sign. In some instances of advertising signage, a transparent display can be used to provide advertising without obstructing a view of either the interior of a store when viewed from the exterior or vice versa, as well as providing an easily changeable design. However, backlit signage without additional lighting is not typically configured to provide general illumination that complies with governmental regulations and industry standards applicable to the environment in which the signage is installed.